Manufacture of bent metal tubes



(No Model.) -2 Sheets-Sheet 1.

A. TAP'LIN.

MANUFACTURE OF BENT METAL TUBES.

No. 351,479. Patented Oct. 26, 1886.

NY PETERS. PhotwLhhogmpher. Washington. D, C.

(No Model.) 2 Sheets-Sheet 2.

. A. TAPLIN.

, MANUFACTURE OF BENT METAL TUBES. No. 351,479

u. PETERS, Pholu-Lllhogmpher. Washington, m;

.UNITE STATES PATE L ALVIN TAPLIN, OF FORESTVILLE, ASSIGNOR TO THEBRISTOL BRASS CLOCK COMPANY, OF BRISTOL, CONNECTICUT.

MANUFACTURE OF BENT METAL TUBES.

SPECIFICATION forming part of Letters Patent No. 351,479, dated October26, 1886.

Application filed Augustfi, 1886. Serial No. 209,749. (No model.)

My invention relates to improvements in the manufacture of bent tubesfrom sheet metal, and the principle object of my invention is toeconomize in the manufacture thereof, especially with reference to asaving in stock.

In the accompanying drawings, Figure 1 represents in side elevation aportion of one part of a bent tube, showing the result of the firstoperation upon one blank. Fig. 2 is a side elevation showinga blankwhich has been thus operated upon at both of its ends. Fig. 3 representsin side elevation one half of a tube which has been operated upon by thefinal swagingdies. Fig. 4 is a plan view of the same. Figs. 5, 6, 7, and8 represent side ele vations and a plan view showing correspondingoperations upon the blank for the other half of the tube. Fig. 9represents .in side elevation the two parts of the tube thus formed andproperly trimmed, so as to match together ready for locking the seam.Fig. 10 is a transverse section of the completed tube. Fig. 11 is atransverse section of said tube in the. c011- ditio'n represented inFig. 9. Fig. 12 is a side elevation of the first swaging-dies for theends of one half of the tube. Fig. 13 is a trans- .verse section on lineas x of Fig. 12, showingthe confronting faces of the dies of said Fig.12. Fig. 14 is a side elevation of the first swaging-dies for the endsof the other half of the lanterns; but it is applicable to themanufacture of other tubes having a bend or elbow from which astraightor comparatively straight member extends.

Heretofore the side tubes for tubular lanterns have been made in theform represented in cross-section, Figs. 10 and 11, and by means ofdies, but instead of having the seam upon both sides follow the samecurve, so as to divide the tube at the elbow into what might be termedan outer and inner half, both seams were formed in one plane, the seamon one side of the tube following the lesser or inner curve, while theseam on the opposite side of the tube followed the greater or outercurve. Such tubes required a special blank, whose contour was insubstantially U form, and involved a great waste of stock in cuttingout.

I form the tube from two ribbons or straight strips of metal, which Icurve and swage at the same time, so as to form an outer and inner halffor each tube.

I will first describe the operation for forming the outer half, a, ofthe tube. One end of a straight strip of metal is placed between theswaging-dies A B, Fig. 12, and subjected to pressure therein, therebyforming an elbowat one end of the tube and swaging the metalinto thedesired shape, as represented in Fig. 1. The other end of the same blankis then operated upon in like manner, in the same die, so as to swagethe other elbow, which action will also bend the intermediate portion ofthe blank into a trough-shaped form, the result of these two operationsbeing represented in Fig. 2. This partially-formed blank, Fig. 2, isthen subjected to the action of the final swagingdies, C D, Fig. 16,thereby forming the metal into the form represented in Figs. 3 and 4.,the same being mainly of semicircular formin cross-section or end view.In lantern-tubes one elbow is generally made on a curve of a largerradius than that of the other elbow, as

AND.

jug-die. I make the blank alittle wider than is necessary for formingthe tubes and leave a portion to be trimmed off, so as to allow for somevariation in placing the blank within the die or slipping after it isplaced between the dies. This surplus metal, which is to be trimmed offfrom the outer part, a, of the tube, is designated by the letter I). Itmay be trimmed off in dies or by any ordinary means, so as to leave thepart a of the tube in the form represented in Fig. 11. The inner half ofthe tube 0 is operated upon in the same manner by means of the dies E Fand G H, which produce the forms represented in Figs. 5, 6, 7, and 8.These forms are also made from a blank which is wide enough to admit oftrimming off the edges of the flange d, to straighten the edges andleave said flanges of the proper width, as shown in Figs. 9,10, and 11.After trimming, the two parts of the tube are placed together, as shownin Figs. 9 and 11, when the edge of the metal composing the part a isclinched down by dies, or in any proper manner, into the formrepresented in Fig. 10, to lock the two parts of the tube together. Theends of the completed tube may be sawed or otherwise cut off to bringthem into the desired form with reference to the parts to which they areto be attached.

Inasmuch as the upper andlower dies in Fig. 13 represent correctly thedies A B, and also the dies (J D, I have omitted all reference-lettersfrom such figure. The reference-letters are also omitted from the upperand lower dies in Fig. 15, which bear the same relation to the dies E FG H. The first or preliminary swaging-dies for either half of the tubeare principally for swaging the elbow, while the final swaging-diesswage the body of the tube and correct any imperfections that may befound in the result of the previous dies. The form of these dies will beunderstood from the drawings. An important feature of them is that theyare divided upon a line which corresponds to the curve of the tube onits longitudinal axis.

Vhile the foregoing is the best mode known to me at present for carryingout my invention, the main advantages of my improvement may be reachedby somewhat different steps and different dies.

The essential or most important feature of my improvement resides instriking the two parts of the tube fromastraight blank or strip with theconnecting seam on both sides of the tube alike and following the curveof the tube on its longitudinal axis. Each part of the tube may be sostruck at a single operation.

By my improvement I make a very large saving of stock, and I alsoproduce a more desirable tube.

I claim as my invention 1. That improvement in the manufacture of benttubes which consists of first forming a straight blank for each half ofthe tube and then striking said blanks to swage them into semicircularform in cross-section, and at the same time bending said straight blanksto give them the proper elbow-curve in side view, the dividing linebetween the two parts of the tube on both sides thereof following thecourse of the tube on its longitudinal axis, substantially as described,and for the purpose specified.

2. That improvement in the manufacture of bent tubes which consists offorming said tubes from two straight strips of sheet metal by firststriking the elbow portions of said strips to give them theirsemicircular form in cross-section, and at the same time to curve thesame, respectively, into the outer and inner halves of the elbows, thenstriking in a final die to complete the portion which extends from theelbow, substantially as de scribed.

3. That improvement in the manufacture of bent tubes which consists offorming said tubes from two straight strips of sheet metal by firststriking separately the respective ends of said strips, to give themtheir semicircular form in cross-section and their elbow-curve in sideview, and then striking in a final die to give form to the portionbetween said elbows and perfect said elbows with reference to saidmiddle portion, substantially as described.

4. The hereindescribed dies for forming the elbow portion of bent tubesfrom strips of sheet metal, said dies having the semicircular form incross-section, while they are divided mainly on a curved linecorresponding to the curve of the tube, substantially as described, andfor the purpose specified.

5. The herein described dies for use in forming bent tubes from straightstrips of sheet metal, said dies having the semicircular form incross-section, while they are divided on a line which corresponds withthe axial line of said tube, involving the curve at each end,substantially as described, and for the purpose specified.

6. As a new article of manufacture, the herein-deseribed bent tubecurved at its elbow portion and with a seam on both sides, which followsthe longitudinal axis of the tube, substantially as described, and forthe purpose specified.

ALVIN TA PLIN.

Witnesses:

C. S. Tnnnnwnr, M. L. TIFFANY.

